After saving and restarting, I walk over to the room with the purple guard to get ready for the wall clip, but... When I take damage while walking into the wall, I don't clip in. What could I be doing wrong? Any help is appreciated.

If your talking about the easy route with the room next to the entrence of Hyrule Castle then after you s+q you cannot get hit as that resets the glitch and you should hit at a specific spot on the left. (see: ).

I had no idea you couldn't get hit. I probably got hit on my way there. This is very helpful, thank you!

yeah you cant get hit after you jump off ledge and s+q. the first time you can get hit without it being a problem.